POSTERIOR STABILISATION OF BURST FRACTURES OF DORSOLUMBAR SPINE

BACKGROUND Injury to spinal cord and spinal column are serious injuries causing death and disability in the young adult population. Spinal injuries have the lowest functional outcomes and lowest rates of return to work after injury of all major organ system. Although the incidence is relatively small, the impact is enormous as measured in terms of catastrophic physical disability, psychological consequences, and the tremendous cost and the demands on the health care system. With advances in medical technology and the increased experience with large number of spinal injuries, the impetus for the development of programmatic approaches in the management of these devastated victims was provided. The management of spinal injuries is continuously evolving. Many different approaches exist in the treatment of these patients; the comprehensive of spinal cord injuries, multidisciplinary speciality approaches which include orthopaedic surgeon, neurosurgeon, urologist, improvement and better quality of life. METHODS Pre-Operative Evaluation: Mode of injury, fracture level, Magerl’s type, preoperative neurologic status, pain experience, sagittal index, post-operative neurologic recovery, vertebral body compression ratio, Cobb’s angle, complications and rehabilitation were studied and compared with the other studies. Pre-operative MRI was done mandatorily in each case. Surgical Procedure: Under general anaesthesia through posterior midline approach to the spine, we exposed posterior elements of vertebrae one above and one below the fractured vertebra under image intensifier control, we inserted pedicle screws into the pedicles of normal vertebra above and below the fractured vertebra. [1] By compression and distraction manoeuvres, also by gentle manipulative manoeuvres we reduced the retropulsed, translated vertebrae, to achieve near anatomical restoration. We used Cotrel-Dubousset pedicle screw instrumentation for posterior spinal fusion one level above and below the fractured vertebra with the bone graft harvested from posterior iliac crest. (Fig. 1) Post-operative Protocols: Postoperatively, intravenous broad-spectrum antibiotics were given for three days with proper back care. Patients were ambulated with the help of Taylor’s brace. Sutures were removed on the 10 th postoperative day and the patients were discharged and followed in the OPD once in two months for one year. At each visit, patients were evaluated with SCIM score, ASIA score and grade and X-rays. Evaluation of pain relief was done according to Visual Analogue Scale (VAS). (Fig. 2). Functional assessment was done with the spinal cord independence measure developed by A Catz et al specifically for patients with spinal cord lesions. SCIM includes the following areas of function: Self–care (0-20) respiration and sphincter management (0-40), mobility (0-40) each area is scored according to its proportional weight in these patients’ general activity. The final score ranges from 0-100. Functional outcome was assessed at 3 weekly intervals up to 31 weeks and the mean SCIM scores were plotted in a graph for all the patients comparing with preoperative average during the course of the study. (Fig-3) RESULTS Out of 25 patients, 15 cases were paraplegic and 10 cases were paraparetic. Most common mode of injury was fall from height constituting 63% either from a building, or from a pole or a tree. The rest were road traffic accidents. Gender incidence was found to be male preponderant with 20 males (80%) and 5 females (20%). Most common age group involved was between 18 to 28 years (16 pts.). Most common vertebral level of injury was L1 followed by T12. Sixteen patients presented to the hospital within 24 hrs. Six patients presented between 24 and 72 hrs. The rest presented a week later to the hospital. The neurological status according to ASIA impairment scale was noted. Thirteen were grade A, 3 were grade B, 6 were grade C and three were grade D at the time of admission. Postoperatively, 4 patients remained in grade A, 5 patients had grade C, 6 patients had grade D and 10 had grade E. All the patients had neurogenic bladder at the time of admission, nine remained neurogenic post-operatively and 16 patients attained normal bladder status. Pain showed an average of 4.73 pre-operative value and an average post-operative value of 1.13 on VAS scale. Radiologically, the mean pre-operative Cobb’s angle was 14.26 degrees and post- operative mean was 3.63 degrees. The mean improvement in Cobb’s angle was 10.63 degrees. The mean vertebral body compression (height) ratio was 60.83 and mean post-operative ratio was 81.66. Improvement was a mean 20.83 in VBHR post operatively justifying the procedure. The mean preoperative sagittal index was 20.43 degrees and mean postoperative sagittal index was 14.6 degrees. Functional outcome was assessed by Spinal Cord Independence Measure score. The mean pre and post-operative scores were 32.26 and 81.53 respectively. Mean improvement in SCIM score was 49.27. This was done at three weekly intervals up to 31 weeks from admission. Bed sores occurred in 5 patients, 8 patients developed UTI, two patients developed upper respiratory infection and two suffered fever in the post-operative period. CONCLUSION Incidence of thoracolumbar spine fractures has a single peak in young adult age group irrespective of the sex of the patient. Incidence is higher in males with almost equal distribution in rural and urban areas. Unlike western hemisphere, the major cause of thoracolumbar spine fracture is fall from height (not the road traffic accidents). Incidence of thoracolumbar spine has got significant relation to the patient’s occupation, especially people working as tree climbers, construction workers. Most common level of fracture of thoracolumbar spine is thoracolumbar junction (T12-L1). Surgical stabilisation of unstable thoracolumbar spine fractures with short segment posterior spinal instrumentation with pedicle screws, indirect decompression, reduction and posterior fixation has a role to play in the management of unstable thoracolumbar spine fractures. In neurological recovery, injury to cauda equina i.e. lumbar spine injuries showed a better prognosis as compared to thoracic spine injuries (cord injury). Fixation helps in early mobilisation and rehabilitation and fusion helps in preventing early implant failure. Fixation not only helps in reducing the incidence of complications associated with recumbence but also provides good pain relief. Restoration of normal anatomy of spine i.e. restoration of vertebral body height prevents the progression of kyphosis thereby providing mechanical stability to the spine